package cn.tedu.sp06.fallback;

import cn.tedu.web.util.JsonResult;
import org.springframework.cloud.netflix.zuul.filters.route.FallbackProvider;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.stereotype.Component;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * 通过zull网关，调用后台商品服务失败时，
 * 会执行这段降级代码，先客户端返回降级结果
 */
@Component
public class OrderFB implements FallbackProvider {
    /**
     * 设置当前降级类，是针对哪个服务的降级类
     * order-service 只针对订单服务降级
     * null或者* 针对所有服务都应用当前降级类
     * @return
     */
    @Override
    public String getRoute() {
//        return null;
//        return "*";
        return "order-service";
    }

    @Override
    public ClientHttpResponse fallbackResponse(String route, Throwable cause) {
        return new ClientHttpResponse() {
            @Override
            public HttpStatus getStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR;
            }

            @Override
            public int getRawStatusCode() throws IOException {
                return 500;
            }

            @Override
            public String getStatusText() throws IOException {
                return "Internal Server Error";
            }

            @Override
            public void close() {
                // 关闭流
            }

            @Override
            public InputStream getBody() throws IOException {
                // JsonResult {code:500, msg:"调用服务失败", data:null}
                String json = JsonResult.err().code(500).msg("调用订单服务失败").toString();
                return new ByteArrayInputStream(json.getBytes("UTF-8"));
            }

            @Override
            public HttpHeaders getHeaders() {
                // Content-type: application/json;charset=UTF-8
                HttpHeaders headers = new HttpHeaders();
                headers.add("Content-Type", "application/json;charset=UTF-8");
                return headers;
            }
        };
    }
}
